package com.lh.project.common;
import cn.hutool.core.lang.UUID;
import com.lh.project.constant.ILock;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;


import java.util.Collections;
import java.util.concurrent.TimeUnit;

public class SimpleRedisLock implements ILock {

    private StringRedisTemplate stringRedisTemplate;
    /**
     * 锁的名称
     */
    private String name;

    private static  final String KEY_PREFIX = "lock:";
    private static  final String ID_PREFIX = UUID.randomUUID().toString(true)+"-";
    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;

    public SimpleRedisLock(StringRedisTemplate stringRedisTemplate, String name) {
        this.stringRedisTemplate = stringRedisTemplate;
        this.name = name;
    }

    static {
        UNLOCK_SCRIPT = new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
        UNLOCK_SCRIPT.setResultType(Long.class);
    }

    @Override
    public boolean tryLock(long timeoutSec) {
        //获取线程的标识
        long id = Thread.currentThread().getId();
        //获取锁
        Boolean success = stringRedisTemplate.opsForValue()
                .setIfAbsent(KEY_PREFIX + name, ID_PREFIX+id, timeoutSec, TimeUnit.SECONDS);
        return Boolean.TRUE.equals(success);
    }

    @Override
    public void unlock(){
        //调用lua脚本
        stringRedisTemplate.execute(UNLOCK_SCRIPT,
                Collections.singletonList(KEY_PREFIX+name),
                ID_PREFIX+Thread.currentThread().getId()
        );
    }
    public void unlock1() {
        //获取线程标识
        String threadId = ID_PREFIX+Thread.currentThread().getId();
        String id = stringRedisTemplate.opsForValue().get(threadId);
        if(threadId.equals(id)){
            //释放锁
            stringRedisTemplate.delete(KEY_PREFIX+name);
        }
    }
}
